کاظم علی آبادی - Faculty member of Hakim Sabzevari University, Razavi Khorasan, Iran
محمدعلی اسدی زنگنه
عباسعلی داداشی رودباری

Introduction: Weather and climate disasters are as inevitable phenomena among climate risks, vulnerabilities and responding to the needs. Iran is located in an area that is severely affected by dust storms. According to the researches, the frequency and intensity of the storms have increased in recent years. In this study, given the importance and determining the characteristics of the most severe cases lead to dust storms and haze; the regional atmospheric circulation assessed and the main source of dust storms identified in the areas by using HYSPLIT model and their path in recent years in the West and South West Iran (in a ۴-day period on March, ۲۰۱۲). Method: This functional study examined remote sensing. However, in order to explain the main causes of dust storms, the structure of regional atmospheric circulation were studied and determined by Using HYSPLIT model and retroviral tracking method. As well as to evaluate and compare the results, the outputs DREAM ۸b model and the optical thickness values of AOT were used. Findings: According to the results, the flow of the lower atmosphere from Iraq (West) blows to the west of Iran during a dust storm. The study of the synoptic maps showed that the regional scale of atmospheric circulation in the lower levels plays the major role in occurrence of dust storms in south and southwest of Iran. However, during the storm, a strong low-pressure center formed in east of Iran; in this situation, west winds penetrate the dust storm to the region. By using HYSPLIT model, the results of tracking the wind showed that the main sources of dust storms are in the north to the northwest of Iraq and east of Syria based on the monitoring AOT data and DREAM ۸b model. Conclusion: In general, dust storm is moved to the country in two paths; first, Northwest to Southeast (Northwest regions of Iraq and East of Syria); second, West to East direction (from the center of Iraq to the Southwest and West of Iran). It was also found that dust particles are transported to the shallow and lowest layer area of the atmosphere. On the day of storm, the particles depth was high (۰/۹); so it can conclude that dust storms in the atmosphere in area studied are very dangerous for the health.

dust storms, optical thickness, the HYSPLIT, the DREAM ۸b, Iran, توفان گرد و غبار, ضخامت نوری, مدل HYSPLIT, مدل DREAM ۸b